The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Evaporative emissions systems collect fuel vapor from a fuel tank and deliver the fuel vapor to an intake system for combustion in an engine. An evaporative emissions system typically includes a canister that absorbs fuel vapor from the fuel tank and a purge valve that controls the flow of fuel vapor from the canister to the intake system. Single path purge systems include a single path extending from the purge valve to the intake system. Dual path purge systems include two paths extending from the purge valve to the intake system.
Dual path purge systems are typically used for engine systems that include a boost device, such as a turbocharger, which pressurizes intake air provided to the engine. In these applications, dual path systems typically include a boosted path that provides fuel vapor to the intake system upstream from the boost device and a non-boosted path that provides fuel vapor to the intake system downstream from the boost device. In various dual path purge systems, the boosted path includes a jet pump that draws fuel vapor through the first path when the boost device is providing boost. The jet pump includes a first inlet in communication with the canister, a second inlet in communication with a location in the intake system downstream from the boost device, and an outlet in communication with the intake system upstream from the boost device.